1. Field of the Invention
The present invention relates to an authentication method, an authentication system, a semiconductor circuit, and an authentication module.
2. Description of the Related Art
In recent years, electronic commercial transactions accompanied with personal authentication using an integrated circuit (IC) card have spread.
An IC card equipped with such a personal authentication function usually stores authentication software in the IC and carries out a predetermined authentication processing by the authentication software by using for example a personal identification number (PIN) input by a user. The result of the authentication processing is transmitted via a network to an authentication apparatus. The authentication apparatus authenticates the legitimacy of the user of the IC card based on the result of the authentication processing in the authentication apparatus.
An IC (semiconductor circuit) of such an IC card is usually mass produced by photolithography utilizing a circuit mask pattern common for all the other ICs. Therefore, the hardware configuration is the same as the ICs of the other IC cards. Easy illegitimate copying of the IC card is prevented by making part of the processing described in the authentication software different from that of the ICs of other IC cards.
Summarizing the disadvantage to be solved by the invention, in the conventional IC card mentioned above, however, copying of the software is relatively easy, so the authentication software stored in the IC ends up being copied and illegitimate copying of the IC card cannot be sufficiently prevented. For this reason, there is a disadvantage in that illegitimate personal authentication ends up being made by using an illegitimately copied IC card and therefore electronic commercial transactions having a high reliability are not possible.